880 PROCEEDINGS OF SECTION J. 



^ Cub, Yds. 



Embankment on line as laid out (5-cliain radius)... 89*106 



Ditto on red line (2J chains) 22-500 



Saving on IJ miles 06*606 



Concrete culverts on line as laid out, lineal yards... 289* 

 Ditto on red line 187* 



Saving on 1^ miles 102* 



Thus in the main items of construction, by the adoption of the 

 narrow gauge a saving would result in first cost of excavation per 

 mile, 42*270 cubic yards ; embankments per mile, 44*404 cubic 

 yards ; culverts per mile, 68 lineal yards. 



A saving would also be effected throughout the whole length 

 of the line in ballast and other minor details, and, exclusive of 

 permanent way, it may be estimated that the narrow gauge could 

 be constructed for about one-third (g) of the cost of the standard 

 gauge. 



In the one and a half miles quoted there would be nine curves 

 of 2^-chain radius, the longest being 5 chains, with several curves 

 of 3-chain radius, in lieu of the curves laid out having radii of 

 5 chains. 



Gradients. — With regard to the proposed alteration from the 

 standard gradient of 1 in 40 to 1 in 33, this would only favour- 

 ably affect several small cuttings and embankments on the flat 

 wround, and the cuttings on the various summits, which in all 

 „ases are light, and 1 therefore do not see any advantage to be 

 obtained in making any alteration in this respect, but great disad- 

 vantage in the working of the line, and very great disadvantage 

 when in the future it is found necessary to resume the standard 

 gauge. I would therefore suggest, in the event of the narrow 

 gauge being determined upon, that the line as laid out be made 

 the base for laying out the narrow gauge line, and that the levels 

 and gradients for the broad gauge line be maintained, so that in 

 those places where the line as laid out will apply to the narrow gauge 

 lines (and this will extend over many miles) the work already 

 done will be an important contribution towards the construction of 

 the standard gauge line. 



Another very important consideration in the matter of levels is 

 the great advantages which would accrue towards the construction 

 of the substituted standard gauge in the delivery of materials all 

 along the line at the levels desired. In broken country such as is 

 represented on the accompanying plan and section, the 2|-chain 

 curves appear to suit the spurs and gullies, and thus the narrow 

 gauge line will throughout be almost a surface line, therefore in 

 many places the cuttings and embankments, and even culverts, 



